One proposed structure of the engine misfire detection apparatus includes an internal combustion engine and a motor generator connected to an output shaft of the internal combustion engine. In the failure of accurate detection of misfires of the internal combustion engine according to a driving condition of a vehicle, this prior art engine misfire detection apparatus restricts or prohibits the detection of misfires of the internal combustion engine (see Patent Document 1). The restriction or prohibition of the detection of misfires in the internal combustion engine in the event of failed detection of the engine misfires with high accuracy according to the driving condition of the vehicle aims to prevent wrong detection of misfires in the internal combustion engine.    Patent Document 1: Japanese Patent Laid-Open No. 2001-317402